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CVE Record

CVE-2020-21047: The libcpu component which is used by libasm of elfutils version 0.177 (git 47780c9e), suffers from denial-...

The libcpu component which is used by libasm of elfutils version 0.177 (git 47780c9e), suffers from denial-of-service vulnerability caused by application crashes due to out-of-bounds write (CWE-787), off-by-one error (CWE-193) and reachable assertion (CWE-617); to exploit the vulnerability, the attackers need to craft certain ELF files which bypass the missing bound checks.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2020-21047 is a denial-of-service flaw in elfutils 0.177-era libcpu/libasm handling of crafted ELF files. If a vulnerable tool processes a malicious ELF file, it may crash. The source bundle does not show data theft, remote code execution, or active exploitation.

Executive priority

Treat this as a targeted availability risk, not a confirmed breach indicator. Prioritize updates for systems that automatically inspect untrusted ELF files. Business urgency is lower for isolated systems that never process external binaries.

Technical view

The CVE describes missing bounds checks in libcpu, used by elfutils libasm, leading to out-of-bounds write, off-by-one behavior, and reachable assertion failures when parsing crafted ELF files. Upstream bug and commit references exist; Debian LTS also published an elfutils security update.

Likely exposure

Exposure is most likely where elfutils libasm/libcpu processes untrusted ELF binaries, such as analysis, debugging, build, packaging, or security scanning workflows. The affected product data in the bundle is incomplete, so confirm installed elfutils versions through vendor package metadata.

Exploitation context

The bundle says attackers need crafted ELF files that bypass missing bounds checks. It does not cite public exploitation, KEV listing, exploit maturity, or network-triggered attack paths. Practical risk depends on whether vulnerable tooling parses attacker-controlled ELF content.

Researcher notes

The record has limited structured affected-product and scoring data. Analysis should focus on the referenced Sourceware bug, upstream commit, and vendor advisories. Do not assume code execution or broad platform impact from the provided evidence alone.

Mitigation direction

  • Apply vendor or distribution elfutils security updates where available.
  • Review Debian LTS DLA 3579-1 if using Debian LTS packages.
  • Check whether upstream commit 99dc63b applies to your maintained elfutils branch.
  • Avoid processing untrusted ELF files with vulnerable elfutils tooling until updated.
  • Use sandboxing for ELF analysis pipelines that must handle untrusted files.

Validation and detection

  • Inventory systems and pipelines that use elfutils, libasm, or libcpu.
  • Confirm whether deployed versions match vulnerable 0.177-era code or vendor-fixed packages.
  • Check distribution advisories for backported fixes, not only upstream version numbers.
  • Review crash reports from ELF-processing workflows for related assertion or bounds failures.
  • Prioritize validation where users, partners, or automation can submit ELF files.
Prepared
Confidence
medium
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
4Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.